Process and apparatus for leveling floors



June 3, 1969' D. G. MARTENS ETA!- PROCESS AND APPARATUS FOR LEVELING FLOORS Filed Feb. 14, 1967 Shet INVENTORS DAV/0 a MARTE/VS EDWARD R cmarr A TToKAI y I KN k N w A /w\ %W b 5% Q F i o 7 June 3,1969 o. G. MARTENS ETAL 3,447,279

PROCESS AND APPARATUS FOR LEVELING FLOORS Filed Feb. 14, 1967 Sheet 3 cr 2 42 4/ 5 40 3 3a 37 I as I/ I r v n i Z f QJ f// 46 45 4 '.'*"""'1 E :r: ,.,../...4 L 2/48 /6, J as /2/ [6/ j INVENTORS DAV/0 GI MARTE/VS BY EDWARD CRAFT A Twelve United States Patent 3,447,279 PROCESS AND APPARATUS FOR LEVELING FLOORS David G. Martens and Edward P. Craft, Princeton, West Va., assignors to the United States of America as represented by the Secretary of Agriculture Filed Feb. 14, 1967, Ser. No. 615,945 Int. Cl. E04g 23/ 00, 21/00; E04b 1/00 US. Cl. 52-741 3 Claims ABSTRACT OF THE DISCLOSURE A nonexclusive, irrevocable, royalty-free license in the invention herein described throughout the world for all purposes of the United States Government, with the power to grant sublicenses for such purposes, is hereby granted to the Government of the United States of America.

BACKGROUND OF THE INVENTION Field of the invention This invention relates to a new and quicker method of establishing a level bearing surface over which new flooring can be laid when it is desired to replace or cover old sagging floors in rehabilitating old buildings.

Description of the prior art In the redecoration and rehabilitation of apartment buildings, oflice buildings or buildings in general, it is desirable to level the floors of said buildings if the floors are uneven or are sagging. In carrying out this operation, numerous methods are employed. One method known to be used is to position and level each screed or joist individually by placing shingles and/or wedges between the floor and the screeds or joists at the necessary positions until the screeds or joists are all level. Besides leveling each screed or joist individually, it is also necessary to level each screed or joist relative to all of the other screeds or joists one at a time. Such a method is very time consuming and costly. Moreover, the screeds or joists are supported only at the points where the shingles and/or wedges have been placed. The latter condition can lead to renewed sagging of the new floor unless screeds or joists that are heavy or strong enough to require only spot support are used.

Summary In general, the principal improvement of the presently described invention resides in the method of establishing a level bearing surface over any irregular, uneven, or sagging surface by prepositioning screeds over the surface, establishing and holding the screeds in the desired plane by use of level adjusting devices, and introducing a rigid cellular plastic foam between the screeds and the surface to be leveled. The screeds, which are held and supported in the level position by the foam, serve in the same capacity as joists in conventional floor construction by providing a level surface to which new subflooring or flooring is fastened. The leveling devices are adjustable 3,441,279 Patented June 3, 1969 to provide a level or straight edge to hold the screeds in their intended plane, and also hold the screeds at the desired spacing while the plastic foam is being introduced between the screeds and the uneven or sagging surface.

Accordingly, one object of this invention is to provide a system that significantly reduces the time required to establish a level bearing surface over irregular, uneven, or sagging floors or subfloors.

Another object is to reduce the cost of leveling old sagging floors.

A further object is to provide an apparatus that will establish the level bearing surface of all the screeds at one time over any subsurface, thus eliminating the need to level each screed individually.

An even further object is to provide continuous support under the entire length of the screeds so that the screeds need only to provide a nailing or attaching surface for the flooring or surfacing material, and said screeds do not have to be heavy or strong enough to provide all the required structural support.

These and other objects which will be apparent to those skilled in the art are achieved in accordance with the invention described in the specification, claims, and in the accompanying drawings.

Brief description of the drawings FIGURE 1 is a side view of the leveling device used in establishing a level bearing surface.

FIGURE 2 is a bottom view of the leveling device in FIGURE 1.

FIGURE 3 is a plan view of a typical set-up of the floor leveling system.

FIGURE 4 is a cross sectional view thereof taken through section line 4-4 in FIGURE 3.

FIGURE 5 is a cross sectional view thereof taken through section line 5-5 in FIGURE 3.

Description of the preferred embodiments More specifically, referring to FIGURES l and 2, the screed leveling device 11 comprises two long aluminum bars 12 and 12' attached together by bands 13 and 13' such that the bars may be adjusted in length by sliding one bar alongside the other. Thumb screws -14 and 14' hold the bars 12 and 12' in position when they have been extended to the desired length. Both ends of each bar are fitted with infinitely adjustable, threadless, heighth adjustment devices indicated generally by reference figures 15, 15', 15", and 15". Since the heighth adjustment devices are all the same in configuration and operation, detailed reference figures will only be shown on device 15. Rod 16 is fitted perpendicular to and through a hole, of slightly larger diameter, in bar 12. The rod, ordinary plumbers pipe, is not permanently attached to the bar, but rather is releaseably engaged with the bar by means of clamping device 17. The clamping device is a spring loaded multiple plate clutch known by the trade name of Pony, is manufactured under US. Patent 1,783,713, and is attached to bar 12 by Weld or rivet along the surface 18. At one end of the rod 16 is a swivel base 19.

Clamping device 17 holds the rod 16 in whatever position the rod is in when clamping lever 20 is released. To move rod 16 and thereby adjust the heighth of end 21 of bar 12, clamping lever 20 is squeezed and rod 16 can be adjusted so as to hold the bar in a raised or lowered position. When clamping lever 20 is released, rod 16 will be held in position. Thus it is seen that the heighth adjustment is infinitely variable and can be accomplished in a minimum of time. Similarly, end 22 of bar 12 and ends 23 and 24 of bar 12' are adjusted to the desired heighth by means of heighth adjustment devices 15, 15", and 15", respectively.

Holes 25 through 35 have been drilled though the bars along their entire length. These holes establish the proper lateral spacing of the screeds and facilitate the attaching of the leveling device to the screeds by means of fasteners, such as duplex-headed nails.

Referring now to FIGURE 3, wood screeds 36 through 42 are placed in approximately their desired positions over the existing floor 43. Leveling devices 11, 11', and 11" are placed over the screeds with the bars 12 and 12 of leveling device 11 and the corresponding bars of leveling devices 11 and 11", positioned horizontally perpendicular to the screeds. At the time of positioning the leveling devices, the rods, generally indicated by 16, are in a retracted position with the swivel bases, generally indicated by 19, against the clamping devices. This permits the leveling devices to be temporaily attached to the screeds by putting fasteners 44 through 50 through the appropriate holes in the leveling bars and into the screeds. Duplexheaded nails are the preferred fasteners. Leveling devices 11' and 11" are similarly attached to the screeds. The leveling bars and attached screeds are then raised to the intended plane, the heighth adjustment rods, indicated by 16, are released to their desired extension by squeezing the clamping lever 20 of each heighth adjustment mecha nism, allowing the rods to fall freely, and the clamping levers are then released. The intended plane may be predetermined by a chalk line around the walls, sight lines, or by whatever means the user desires. Carpenters levels may also be used and are preferred. By attaching all the screeds to the leveling devices at one time, the screeds may all be leveled at the same time and held in this leveled position.

With the screeds in theirraised position, a bead frothed rigid urethane foam indicated by 51 through 57 is introduced between the bottoms of the screeds and the irregular floor. The foam is introduced under the full length of the screeds and expands to its maximum dimension in less than one minute and cures to eighty (80) percent of its final strength in less than eight (8) minutes. The floor, as shown in FIGURES 3, 4, and 5, sloped toward the upper right corner in FIGURE 3. The screeds are now all in a level plane indicated by the plane 58 shown as the top of screed 40 in FIGURE and the tops of the screeds 36 through 42 in FIGURE 4. After the elapse of the eight minute cure time, the fasteners are removed from the screeds, and the leveling devices are detached. The screeds and their rigid urethane foam base serve as new false joists and are ready for the installation of new flooring. Because of its strength, the rigid urethane foam can provide all of the support required, and the screed need only be of sufficient strength and holding power to provide a nailing surface or attaching surface for the new flooring.

By using the method herein described, two men'can complete the installation of the screeds, from start to finish, in a 12 foot by 12 foot room in less than fifteen (15) minutes.

The preferred foam is a rigid urethane foam, but any other cellular plastic foams, such as polystyrene, can also be used. It is likewise preferred that the urethane foam be applied in a frothed state because it can be more easily controlled since the frothed foam only has to expand to about six times its size to reach full expansion. It is there fore easier to estimate the amount to apply than if the foam is applied in a liquid state, in which state the foam expands to about thirty times its size to reach full expansion. However, the foam that results from either application method is exactly the same and either method can be used to attain the desired foam support structure.

It is understood that the embodiments described herein are merely illustrative of the presently described invention, and numerous modifications, readily apparent to those skilled in the art, could be incorporated herein. The number of leveling devices used is dependent on the size of the room to be leveled and is not meant to be limited to two. Similarly, the number of heighth adjustment mechanisms per bar is not fixed at two, but is dependent on the length of the bar used. It is intended that as many heighth adjustment mechanisms be used as are necessary to hold the leveling bars and screeds in the desired plane. If very long bars are used, it may be necessary to use three or more heighth adjustment mechanisms per bar; if short bars are used, then only two heighth adjustment mechanisms may be needed. Also, other heighth adjustment mechanisms, such as screw jacks will work and have been used in developing this invention. It is further understood that the leveling devices and the leveling process herein described can be used to establish inclined planes also if the user desires, but it is anticipated that the most desirable use of the system will be to establish a level plane. It is still further understood that the process is not restricted to the leveling of uneven or irregular floors. This invention can be used anywhere that it is desired to establish a level or inclined plane over any surface. For example, a temporary bandstand or dance floor could be quickly set up on bare ground by using the system herein described to establish a level plane.

Because of its strength to weight ratio characteristics, aluminum is preferred as the material for the leveling bars, but other structural materials, such as cast metal, iron, steel, and wood are also satisfactory. It is also understood that other means of fastening the leveling devices to the screeds might be used instead of nailing; for example, clamps might be employed. Providing holes in the leveling device bars and nailing through the holes into the screeds has been found to be the preferred method however. Wood beams are preferred for the screed material, but other materials, such as plywood, particle board, chip board, pressed wood, and even metal joists are suitable. Since the cellular plastic foam base provides all the necessary support, the screeds only have to provide a nailing or attaching surface for the laying of the flooring material.

Having thus disclosed our invention, we claim:

1. The method of leveling floors comprising prepositioning screeds at the desired spacing over the existing floor, adjusting the height and level plane of the screeds and holding said screeds in said level plane by means of height and level adjusting devices, introducing a frothed foam between the screeds and existing subsurface and causing said foam to expand into contact with the bottom of said screeds, allowing said foam to become rigid, then removing said height and level adjusting devices whereby said foam which has expanded into contact with the bottom of said screeds and became rigid supports said level screeds.

2. The method of claim 1 wherein the frothed rigid foam is frothed rigid urethane foam.

3. The method of claim 1 wherein the frothed rigid foam is frothed rigid polystyrene foam.

References Cited UNITED STATES PATENTS 1,783,713 12/1930 Holman 269--168 1,788,315 1/1931 McWilliams 52365 1,820,041 8/1931 Barrows 52366 2,637,313 5/1953 White 248410 2,968,051 1/1961 Imber et al. 5181 3,194,853 7/1965 Weise et a1 52--127 3,302,362 2/1967 Lang 52743 3,362,120 l/l968 Warren 52366 FRANCIS K. ZUGEL, Primary Examiner.

US. Cl. X.R. 

